生活饮用水中8种挥发性卤代烃的测定及其致癌风险评估

目的 建立自动顶空-气相色谱法同时测定生活饮用水中二氯甲烷、三氯甲烷、1,2-二氯乙烷、四氯化碳、一溴二氯甲烷、二溴一氯甲烷、四氯乙烯及三溴甲烷，并进行致癌风险评估。方法 顶空瓶中加入10 ml水样，加入氯化钠1.0 g，在55℃下平衡30 min后，顶空气进入气相色谱仪分析。采用HP - 5（30 m×320 μm，0.25 μm）毛细管色谱柱进行分离，电子捕获检测器（ECD）检测。结果 8种卤代烃的相关性系数（r值）为0.9995～0.9999，相对标准偏差（RSD）为2.3%～3.8%，加标回收率为93.1%～103.5%，检出限为0.06～4.92 μg/L。采用本方法测得佛山市某地区6个镇24份饮用水中8种卤代烃的浓度为5.70 ～35.11 μg/L，总致癌风险分别为1.704×10 - 5、1.096×10 - 5、1.374×10 - 5、1.993×10 -5、5.860×10 - 6和1.116×10 - 5，其中主要致癌因子为一溴二氯甲烷。结论 本方法准确、快速、简便，适用于生活饮用水中8种卤代烃的检测。采样地区的饮用水中卤代烃可能具有潜在致癌风险，但非致癌健康风险很小。

Determination of eight volatile halogenated hydrocarbons in drinking water and their carcinogenic risk assessment

Objective To establish an automatic headspace-gas chromatography method for the simultaneous determination of eight halogenated hydrocarbons (CH2Cl2, CHCl3, ClCH2CH2Cl, CCl4, CHBrCl2, CHBr2Cl, C2Cl4, CHBr3) in drinking water and assess their carcinogenic risk. Method: 10 mL water sample was added into the headspace bottle, 1.0 g NaCl was added, the samples was equilibrated at 55°C for 30min, and then the head-space gas was analyzed by gas chromatography. A HP-5 (30 m×0.32 mm, 0.25 μm) capillary column was used for separation, and the ECD was used for detection. Results Under the experimental conditions, the linear correlation coefficients(r) were 0.9995-0.9999. The relative standard deviations (RSDs) were 2.3%-3.8%, and the recoveries ranged from 93.1%～103.5%, the detection limits were 0.06 μg/L-4.92 μg/L. The method was applied to determination of the eight halogenated hydrocarbons in 24 drinking water samples from 6 towns in Foshan, giving mass concentration in the range of 5.70 μg/L-35.11 μg/L. The total cancer risks were 1.704×10-5, 1.096×10-5, 1.374×10-5, 1.993×10-5, 5.860×10-6 and 1.116×10-5, respectively. The most important carcinogenic factor was CHBrCl2. Conclusion This method is rapid, simple and precise. It is suitable for the accurate detection of 8 halogenated hydrocarbons in drinking water. Halogenated hydrocarbons in drinking water of the six towns have potential cancer risk to humans.